On April 2 and April 3, 2025, the Internal Revenue Service (IRS) announced that petitions have been filed to add the following chemicals to the list of taxable substances:

• Polyisobutylene (90 Fed. Reg. 14521): Petition filed by TPC Group, Inc., an exporter of polyisobutylene;
• Acrylonitrile butadiene styrene (90 Fed. Reg. 14687): Petition filed by Trinseo LLC, an importer and exporter of acrylonitrile butadiene styrene;
• Acrylonitrile-butadiene rubber (90 Fed. Reg. 14684): Petition filed by Arlanxeo USA LLC and Arlanxeo Canada Inc., importers and exporters of acrylonitrile-butadiene rubber;
• Chloroprene rubber (90 Fed. Reg. 14691): Petition filed by Arlanxeo USA LLC and Arlanxeo Canada Inc., importers and exporters of chloroprene rubber;
• Emulsion styrene butadiene rubber (90 Fed. Reg. 14692): Petition filed by Michelin North America, Inc., an importer of emulsion styrene butadiene rubber;
• Emulsion styrene-butadiene rubber (90 Fed. Reg. 14686): Petition filed by Arlanxeo USA LLC and Arlanxeo Canada Inc., importers and exporters of emulsion styrene-butadiene rubber;
• Ethylene vinyl acetate (VA < 50 percent) (90 Fed. Reg. 14688): Petition filed by Arlanxeo USA LLC and Arlanxeo Canada Inc., importers and exporters of ethylene vinyl acetate (VA < 50 percent);
• Ethylene vinyl acetate (VA ≥ 50%) (90 Fed. Reg. 14683): Petition filed by Arlanxeo USA LLC and Arlanxeo Canada Inc., importers and exporters of ethylene vinyl acetate (VA ≥ 50 percent);
• Ethylene-propylene-ethylidene norbornene rubber (90 Fed. Reg. 14695): Petition filed by Arlanxeo USA LLC and Arlanxeo Canada Inc., importers and exporters of ethylene-propylene-ethylidene norbornene rubber;
• Hydrogenated acrylonitrile-butadiene rubber (90 Fed. Reg. 14686): Petition filed by Arlanxeo USA LLC and Arlanxeo Canada Inc., importers and exporters of hydrogenated acrylonitrile-butadiene rubber;
• Hydrogenated acrylonitrile-butadiene rubber (90 Fed. Reg. 14685): Petition filed by Zeon Chemicals L.P., an importer and exporter of hydrogenated acrylonitrile-butadiene rubber;
• Isobutene-isoprene rubber (90 Fed. Reg. 14689): Petition filed by Arlanxeo USA LLC and Arlanxeo Canada Inc., importers and exporters of isobutene-isoprene rubber;
• Solution styrene-butadiene rubber (90 Fed. Reg. 14690): Petition filed by Arlanxeo USA LLC and Arlanxeo Canada Inc., importers and exporters of solution styrene-butadiene rubber;
• Bromo-isobutene-isoprene rubber (90 Fed. Reg. 14694): Petition filed by Arlanxeo USA LLC and Arlanxeo Canada Inc., importers and exporters of bromo-isobutene-isoprene rubber;
• Poly(ethylene-propylene) rubber (90 Fed. Reg. 14690): Petition filed by Arlanxeo USA LLC and Arlanxeo Canada Inc., importers and exporters of poly(ethylene-propylene) rubber;
• Solution styrene-butadiene rubber (90 Fed. Reg. 14693): Petition filed by Michelin North America, Inc., an importer of solution styrene-butadiene rubber; and
• Styrene-acrylonitrile (90 Fed. Reg. 14693): Petition filed by Trinseo LLC, an importer and exporter of styrene-acrylonitrile.

Comments on the petitions are due June 2, 2025. More information on the Superfund excise tax on chemicals is available in our July 13, 2022, memorandum, “Superfund Tax on Chemicals: What You Need to Know to Comply” and our May 19, 2022, memorandum, “Reinstated Superfund Excise Tax Imposed on Certain Chemical Substances.”